In 1960, the designation was moved to the newly completed Fort Pitt Bridge to cross the Monongahela River due to the closing of the Point Bridge.  Then it turned onto a portion of Penn Avenue to Fort Pitt Boulevard and back to the original alignment.  In 1961, the southern terminus was moved to the northern approach to the West End Bridge.

In 1982, a northern disconnected section was signed from US 19 at the northern end of the West End Bridge to Wexford.  The designation followed Western Avenue, West Ohio Street, circled Allegheny Center on the Commons, East Ohio Street, East Street, and McKnight Road.

Tragedy struck on February 16, 1983 when a rockslide took place at 1:45 PM affecting the northbound lanes between Woodruff Street and Crane Avenue.  It happened 10 minutes after workers had set off 17 small ammonia nitrate charges to clear rocks off the slopes along the northbound side.  Ram Construction Company of Canonsburg had a contract with the City of Pittsburgh to perform the work but sub-contracting the blasting to Controlled Blasting, Inc. of Zelienople.  The city hired them after falling rock closed the right northbound lane in April 1982.  Workers had stopped traffic on either side of the slope when the blasting occurred at 1:33 PM; however, they let traffic through when it appeared that no additional rocks were falling.  The blasting may have loosened mud behind a boulder just enough to make it fall to the roadway below.  Norman Flint, a University of Pittsburgh professor in Geology, speculated that ice could have formed in cracks in the sandstone and the warm weather that day, caused it to melt which loosened more rock.  "This is just what the project was supposed to prevent," said Louis Gaetano, Pittsburgh's Public Works Director.

In all, an estimated 500 tones of sandstone, landed first on top of the bulldozer being operated by Andrew Burgan of Finleyville.  He had managed to leap off of it when workers on the ledge shouted a warning, but the boulder landed on him after crushing the bulldozer, killing Burgan instantly on his 36th wedding anniversary.  The boulder also crushed a white Ford Pinto being driven Ronald Miller, who had just gotten married, purchased a house, and whose wife was expecting a baby at the end of April that year.  "I'm angry," said Mrs. Carla Miller.  "It's just so unfair."  The boulder also crushed the passenger-side of the cab of a Kroger tractor-trailer, throwing the driver, Robert Hilditch of North Royalton, Ohio.  Motorists ran to his aid after he landed on the pavement.  "It was just like something you see in the movies," said Gary Namiotka of the Southside, who was sitting in his car waiting to go past the slope when the landslide occurred.  Saw Mill Run Boulevard remained closed until the following afternoon.

Unrelated to the accident, Ram Construction had been beset by financial difficulties including nearly losing its insurance coverage in January 1983 for failure to pay its premiums.  It did file for bankruptcy protection on January 21, and would have lost it's insurance four days later.  US Bankruptcy Judge Joseph L. Cosetti fortunately ordered the coverage reinstated and instructed Ram to pay the premiums.  He modified that order on February 5 at the request of the insurance company for coverage to end at 11:59 PM on February 24.

In 1984, the alignment was changed with northbound traffic using Western Avenue, Allegheny Avenue, North Shore Drive, General Robinson Street, Anderson Street, River Avenue, and Voeghtly Street.  Southbound traffic was moved to Reedsdale Street and Beaver Avenue.  In 1989, the designation was moved onto I-279 to form a complete Truck US 19 from Mount Lebanon to Wexford after the Parkway North was completed.

Construction began in 1997 on the interchange at the southern portal of the Liberty Tunnel which was completed on November 20, 1999.

With a long history of dangerous driving conditions along West Liberty Avenue, an improvement project began in July 2010.  The road was resurfaced, first from McFarland Road in Dormont to Wenzell Avenue and Brookline Boulevard.  Old asphalt was milled and repairs made to the concrete base, broken curbing was fixed, and traffic and pedestrian signals were updated and retimed, and the roadway was restriped for four lanes of travel.  The second phase of work, from Wenzell Avenue to the South Busway started in Spring 2011 due to gas line replacement work the year before.  Complicating the project was the excavating of a 22-foot-wide strip in the center of the street to remove the old streetcar rails that were buried beneath the pavement.  West Liberty Avenue was restriped from Wenzell Avenue north to Saw Mill Run Boulevard from two wide lanes and a center turn lane, to two narrow lanes, as one resident noted, in both directions and the center turn lane.  The $7.3 million project concluded in Fall 2011, and about a year later, won an ASHE (American Society of Highway Engineers) Pittsburgh Section Outstanding Highway Engineering Award.

Driving became hazardous the night of February 21, 2011 when eight inches of snow fell in the Pittsburgh area.  About a dozen vehicles became stranded on the ramp from Interstate 279 to McKnight Road, prompting PennDOT to close it until plow trucks could come out to salt the roadway.  The drivers who had to abandon their vehicles returned the following day to retrieve them.